Improvement in slide-valves for steam-engines



UNITED STATES NELSON JOHNSON, OF JASPER, NEW YORK.

IMPROVEMENT IN SLIDE-VALVES FOR STEAM-ENGINES.

Speciiication forming part of Letters Patent No. 139,793, dated June 10, 1873; application led February 5, 1873.

To all whom it may concern Beit known that I, NELSON JOHNSON, of Jasper, in the county of Steuben and in the State of New York, have invented certain new and useful Improvements in Valve for Steam- Engines; and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon, making a part ot' this specification.

The nature of my invention consists in the construction and arrangement of a cushion slide-valve for steam-engines, as will be hereinafter more fully set forth.

In order to enable others skilled in the art to which my invention appertains to make and use the same, I will now proceed to describe its construction and operation, referring to the annexed drawing, in which-L- Figure 1 is a perspective view, and Fig. 2 a longitudinal vertical section, of my valve. Fig. 3 shows modifications of the same.

A represents the valve-seat, provided with `steam-ports a a, and exhaust-ports b, and B is the sliding-valve-all constructed and ar' ranged in any of the known and usual ways. In each end of the valve are made two or more rows of small holes d d. The holes of one row come out on the under side ofthe valve just as near as possible to the end; the next row a little further from the end,and the third row still a little further from the end, and so on, all the holes being drilled a little inclined or slanting, as shown in Fig. 2. On the top of the valve in the holes d d, or rather in as many of these holes as may be desired, are placed screws or plugs e e, so as to open just as manylioles as y may be necessary to let in justthe amount of ,f

the dead-center before the valve commences opening a full port acrossV the ends, which will do away with the pounding of the en-` gine, asis the case wh'ei'e there is too much` steam thrown in while the engine 1s on the 1 dead-center.

ln pla-ce of theholes and plugs above deup if scribed I may use either of the modilications shown in Fig. 3, viz., a port, f, with 'slide h on top of the valve; or grooves i with slide v mgion the end of the valve to answer the same purpose.

Having thusfullydescribed my invention,

what I claim as new, and desire to secure by p L The holes d d, with the plugs-e e or their equivalents, arranged in the ends ot' a slidevalve, B, substantially as and for the purposes herein set forth.

In testimony that I` claim the foregoing I y have hereunto set my hand this 9th day of January, 1873.

, NELSON JOHNSON.

Witnesses:

S. OOUNTRYMAN, ANDREW P URDY. 

